Mild
hypoglycemia is common in clinical practice. Severe
hypoglycemia results in
heat shock protein and associate co-chaperone changes. Whether mild prolonged
hypoglycemia elicits a similar response with inflammatory and oxidative-stress responses compared with a severe
hypoglycemic event is unclear; therefore, this pilot exploratory study was undertaken. We performed a case-control induced
hypoglycemia clamp study, maintaining
blood glucose at 2.8 mmol/L (50 mg/dL) for 1 h in 17 subjects (T2D (n = 10); controls (n = 7)). Blood sampling was performed at baseline,
hypoglycemia, and 24 h; slow off-rate modified aptamer (
SOMA)-scan
plasma protein analysis of HSP-related
proteins, inflammatory stress markers, and oxidative stress markers was performed. In total, 16 HSPs were analyzed. At baseline, TLR4:MD-2 complex was elevated (p = 0.01), whilst HSPA8 was lower (p < 0.05) in T2D. At
hypoglycemia, UBE2N, STIP1, and UBE2L3 increased (all p < 0.05), whilst TLR4:MD-2 and HSPA8 decreased (p < 0.05) in T2D versus baseline. In follow-up after
hypoglycemia, HSPs normalized to baseline by 24 h, except UBE2L3 (p < 0.05), which was decreased in controls versus baseline. Correlation of altered inflammatory markers with HSPs revealed the following: at baseline, TLR4:MD-2 correlated with CXCL10 (p < 0.01) and SIGLEC1 (p < 0.05) in controls; HSPA8 negatively correlated with
IL5 (p < 0.05) in T2D. A negative correlation between urinary
isoprostane 8-iso PGF2α, a marker of oxidative stress, and HSPA1A was seen at 24 h in T2D only (p < 0.05). In conclusion, the HSP changes seen for mild prolonged
hypoglycemia were similar to those previously reported for a severe event. However, mild prolonged
hypoglycemia appeared to elicit an increased inflammatory response that was associated with heat shock and related
proteins.